Question

2. a) Balance the following under the conditions described b) State the number of electrons transferred c) Write a reaction quotient for each of the two final balanced reactions. d) determine Ecell for each A) PbOgs) r (aq)→ Pb+2aqi + las) under acidic conditions + B) Als) Mno) Mn02s) + Al(OH) under basic conditions

Answer 1

Answer:

PbO2s)+r (aq)? Pb aq)+12(s) under acidic conditions split in to two that is oxidation and reduction Pb-402-2(s) ? Pb-2(aq)-Reduction I (aq) 212s) - oxidation balance separately Pb-402-2(s) ? Pb-2(aq) + 2 H2O pb-402-2(s) + 4H2O ? Pb-2(aq) + 2 H2O-oxygen balanced now charge need to be balanced, 2+ charge excess on right side Pb-402 2s)+4H20+2e-? Pb ag) 2 H20 21 (aq) 212(S) now combine Pb402 2(s)4H20 2e- +2 (aq)? Pb 2aq)+2H20+12(s) 2e-transferred. Reaction quotient, Qc [product]/ [reactant 2 Als)+MnO4 (aq) ? MnO2(s) Al(OH)4 (aq) under basic conditions (add OH-instead of H+) Al(s)? Al(OH)4 Mno4 (aq)? Mno2(5) balance Al reaction or oxidation : Al(s) 4 OH? AOH)4+3e- then, 2H2O 3e-+Mno4(aq)? MnO2(s)+4 OH

charges (-4) are equal and number of atoms are equal on both side. 3 e- transferred Now combine together, 3 e- and 4 OH- will canceled each other, Al(s) 2H2o+Mno4 (aq)?Al(OH)4+Mno2s) reaction quotient, Qc [Al(OH)41 [Mno2(s)1/[AS)[H2OPIMnos (aq)